The field of this invention is "oral compositions" which term is used herein to designate products which in the ordinary course of usage are retained in the oral cavity for a time and in a manner sufficient to contact essentially all of the dental surfaces, but are not intentionally ingested. Such products include, for example, dentifrices, mouthwashes, prophylaxis pastes and topical solutions.
The bis-biguanide compounds of the present invention are known as effective anti-plaque agents which demonstrate anti-caries activity. However, when compositions containing these compounds are used continuously in a program of oral hygiene, a rather offensive brown stain forms on the oral surfaces which is resistant to removal by ordinary brushing with conventional dentifrices. Thus, prior art compositions containing these bis-biguanide compounds are not cosmetically acceptable. The present invention overcomes this stain problem.